Normally, you should keep backups of your game directory. Ideally, you back up the game directory after each hosting, and all TRN files just before the next hosting. If something goes wrong, you can restore the game directory as a whole.
Usually, it suffices to have backups for the last three turns. Nowadays, disk space is cheap, so you can also back up the whole game.
When you did not heed the above advice, you can still recover from partial data loss. You need:
- an older game directory backup
- all TRN files used after that. You probably still have them in your mailbox.
- all host.log files, or, at least, the random number seeds logged in them
- a pot of coffee
Let's assume your backup is from turn 17. Copy all TRN files for turn 17 into the game directory, and re-run PHost with the same random seed which your original turn-18 host.log says. For example, you could use phost -s 13285 gamedir. You now have a game directory which is in turn 18 which is identical to the original turn-18 game directory except for the timestamp.
Copy all turn-18 TRN files into that directory, and re-run PHost with the original turn-19 random seed. You need the -F flag this time, otherwise PHost will complain about files being stale. Repeat these steps while drinking the coffee, until you are at the turn you wished to restore. Good luck.
► Note: This only works when you use the very same PHost version to re-run each turn which you used to run it in the first place. This also only works when you do not use add-ons that themselves include random actions.
► Note: You can also replace the coffee by another beverage of your choice. Do not use whiskey, though, that will cause you to mis-type numbers.
